Burner plate,in particular for forced-draft oilgas or gas burners

ABSTRACT

A blank to be coned into a burner plate for a forced draft burner has rows of openings extending thereacross. Strips are formed having a longitudinal rib with wings at each side of the rib. Each strip is positioned with its rib between a respective pair of rows of openings, and secured to the plate, with the wings projecting outwardly over said rows to form expansion chambers. The blank with the strips thereon is then coned.

United States Patent Reichniann et al.

[54] BURNER PLATE, IN PARTICULAR FOR FORCED-DRAFT OILGAS OR GAS BURNERS Inventors: Horst Reiclimenn, Wuppertal-Elberfeld; Gernot Rottmann, Lache, both of Gennany Joli. Vaillant KG, Berghauser, Germany Filed: July 6, 1971 Appl. No.: 159,602

Assignee:

Foreign Application Priority Data Sept. 14, 1970 Austria ..8288

2/1921 Cole ..239/5$9 X Oct. 31, 1972 1,389,107 8/1921 Torrey ..239/$53.3 1,610,542 12/1926 Wilson ..239/557X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-John J. Love Attarney-1-loward l-l. Darbo et a1.

[57] ABSTRACT A blank to be coned into a burner plate fora forced draft burner has rows of openings extending thereacross. Strips are formed having a longitudinal rib with wings at each side of the rib. Each strip is positioned with its rib between a respective pair of p I rows of openings, and secured to the plate, with the wings/projecting outwardly over said rows to form expansion chambers. The blank with the strips thereon is then coned.

4 Claims, 4 Drawing Figures PATENTED T 31 2 3. 701 48 l INVEN ORS BY W m BACKGROUND AND SUMMARY OF THE INVENTION The invention relates, to a burner plate of conical shape constructedfrom a flat sheet metal blank of perforated plate, in particular for forced-draft oilgas (gasified oil) or. gas burners.

Burner plats produced from perforated sheet are knowmSuch burner plates may beflat or they may be shaped inthe'form of a spherical section or of a truncated cone. A flat burnerplate has noformstability. Moreover, it suffers from the disadvantage. that dust (e.g., soot), which drops from the burner shaft, is deposited on theburner plate and may thus impair the apertures. The'middle zone of-a-spherical burner plate is subject to the same defects since the dust, which drops onto the said middle zone, may also clog the apertures. The dust is able to slide outwardly only on the inclined parts ofthe spherical burner. plate. As regards the accumulation of dust, the conical shape is better since the dust particles are able to roll off from all sides of the burner plate aperture surface.

Fresh air is supplied to the fuelinlforced-draft oilgas or gasburners after preheating in amixing chamber. The mixing chamber is covered by a burner plate in the form of an outlet cone. i

It is known that the flames emerging from said apertures in the burner plate occasionally tend to lift off. It is furthermore known thatsuch lift-off of the flames may be avoided bylthe use of expansion chambers caus ing stable and adhering flames to beformed onsuch chambers. Such expansion chambers are formed by means of sheet metal strips attached to the burner. Such stable and adhering flames preventlift-off of the main burner flames.

Sheet metal strips for forming expansion chambers cannot, however, be easily attached to a burner inlet surface of conical shape. For example, if sheet metal strips to form expansion chambers are to be applied to a burner plate of conical shape along the surface lines of the said cone, the adjacent ends of the strips in the area of the cone apex would all be positioned closely adjacent each other so that no'surface would remain for the mainflame. At the base of the cone, on the other'hand, the areas of the cone having apertures for the mainflames would be so large that part of the main flamewould remain unsupported by an adhering flame.

The object of the invention is to provide a burner plate of conical shape, constructed from a flat sheet metal blank having sheet metal strips for forming ex-- pansion chambers so that adhering flames, uniformly distributed over the burner plate surface, may be produced.

According to the invention this is achieved in that straight sheet metal section strips for forming the ex-' pansion chambers are placed upon the flat sheet metal blank forming the burner plate and are deformed together therewith so that adhering flames, preventing lift-off of the flame from the burner plate, are produced in uniform distribution over the surface of the conical burner plate after shaping into a cone.

The sectioned sheetmetal strips may be attached to the top of the burner plate. However, in view of the problem of dirt accumulation it is advantageous if the 2 sectioned sheet metal strips are positioned on the underside of the burner plate. Y

The sectioned sheet metal strips may have a rib extending longitudinally midway between two straight rows of apertures of the sheet metal blank and joined to the blank. Said strips have flat edges on both sides of the rib, with the edges being slightly inclined towards the sheet metal blank and extending over said rows of apertures.

DESCRIPTION OF THE DRAWING being shaped into the conical burner plate.

DESCRIPTION OF SPECIFIC EMBODIMENT InFIG. l the numeral 1 refers to a mixing chamber for a burner and formed from a truncated conical shell la. At its bottom this shell is attached to brackets 2 secured to a guide sleeve 3 of a gas nozzle or an oil spraying nozzle 4. At the top the mixing chamber is closed by a conical upper burner plate 8 of perforated sheet metal. Plate 8 has an apex angle which is relatively large compared to theapex angle of the truncated.

conical shell la. The lower cone la of the mixing chamber has apertures for the entry of forced air into the chamber 1. Airalso enters through an aperture 5 at the lower end of the lower cone. The forced air draft is passedin known manner, not, shown, from the outside at the top downwardly along a heating shaft shell 6 of the combustion chamber 7 where the air is heated before being conducted into the mixing chamber 1.

The conical burner plate 8 is positioned at the bottom of a combustion chamber 7 defined by the heating shaft shell 6. .A flanged edge 8' of the burner plate 8 bears sealing-tight at 9 on the heating shaft shell 6. The mixing chamber shell la is joined at 10 to the burner plate 8.

Sheet metal strips 11 are spot-welded on the underside of the burner plate 8 and form expansion chambers 15. The sheet metal strips 11 have a rib 12 disposed along their middle line with wings extending'outwardly at each side of the rib.This rib can .be formed by embossing (roll forming) or by bending the metal in a brake. This rib bears against the burner plate 8 and is positioned between two straight rows of apertures 13.

. The wings of the sheet metal strip 111 on both sides of the rib 12 are slightly inclined towards the burner plate and extend over the aforementioned rows of apertures 13. In this way, expansion chambers 15 are formed. The fuel mixture enters into chambers 15 through. gaps 14 from the mixing chamber 1. Accordingly, the fuel mixture expands in the chamber 15 (because the inlet area is smaller than the outlet area) and emerges at 13. Adhering flames are therefore formed on the apertures 13 which prevent the adjacent main flames, supplied directly from the mixing chamber 1 and emerging from the apertures 16, from lifting off.

As shown in FIG. 4, the burner plate 8 is constructed of a circular sheet metal blank 17 having a sectorshaped cut-out defined by edges 18. The sheet metal blank is perforated to form openings 13 and 16 (only a few of which are shown in FIG. 4). The sheet metal strips 1 l are positioned parallel to each other at identical spacings on the sheet metal blank. The sheet metal blank is then formed into a cone, the edges 18 of the said cone being joined to each other by means of hard soldering. The deformation of the flat blank into a cone is also accompanied by a corresponding co-deformation of the sheet metal strips 1 1. This feature, however, does not alter thefact that the adhering flames are uniformly distributed over the surface of the burner plate.

As already mentioned, it is advantageous if the sheet metal strips are so disposed that they are situated on the interior or underside of theburner plate 8. This is advantageous in view of the risk of dirt pollution. If the sheet metal strips 11 are surmounted on the outside of the burner plate 8, the fuel mixture will flow through the apertures 13 and the expansion chambers 15 and the adhering flames will emerge from the gaps 14.

We claim:

1. In a forced-draft burner having a mixing chamber which terminates in a burner plate of conical configuration made from a metal blank having rows of openings therethrough which is then cone bent to form the burner plate, the improvement wherein said blank has a plurality of straight metal strip means extending substantially parallel to each other in juxtaposition to some of said rows of openings and forming expansion chambers between the blank and the'strip means, parts of said strip means being spaced from said blank to define gaps for the passage of fluid, said strip means beingbent along with the blank when the plate is formed.

2. In a burner as set forth in claim 1, wherein said strips are on the mixing chamber side of said plate.

3. In a burner as set forth in claim 2, wherein each said strip has a rib projecting outwardly at one side thereof, said rib being against said plate and secured thereto, each said strip having wings extending outwardly and spaced from said plate with said spacing being greater at the rib end of the wing than at the distal end of the wing, each said wing being over a row of openings.

4. In a burner as set forth in claim 1, wherein each said strip has a rib projecting outwardly at one side thereof, said rib being against said plate and secured thereto, each said strip having wings extending outwardly and spaced from said plate with said spacing being greater at the rib end of the wing than at the distal, end of the wing, each said wing being over a row of openings. 

1. In a forced-draft burner having a mixing chamber which terminates in a burner plate of conical configuration made from a metal blank having rows of openings therethrough which is then cone bent to form the burner plate, the improvement wherein said blank has a plurality of straight metal strip means extending substantially parallel to each other in juxtaposition to some of said rows of openings and forming expansion chambers between the blank and the strip means, parts of said strip means being spaced from said blank to define gaps for the passage of fluid, said strip means being bent along with the blank when the plate is formed.
 2. In a burner as set forth in claim 1, wherein said strips are on the mixing chamber side of said plate.
 3. In a burner as set forth in claim 2, wherein each said strip has a rib projecting outwardly at one side thereof, said rib being against said plate and secured thereto, each said strip having wings extending outwardly and spaced from said plate with said spacing being greater at the rib end of the wing than at the distal end of the wing, each said wing being over a row of openings.
 4. In a burner as set forth in claim 1, wherein each said strip has a rib projecting outwardly at one side thereof, said rib being against said plate and secured thereto, each said strip having wings extending outwardly and spaced from said plate with said spacing being greater at the rib end of the wing than at the distal end of the wing, each said wing being over a row of openings. 